A set of final examination grades in a course is normally distributed with a mean of 73 and a standard deviation of 8.  

1. What is the probability of getting a grade below 91 on the exam?  
2. What is the probability that a student scored between 65 and 89?  
3. If the professor grades on a curve (gives A’s to the top 10% of the class, regardless of the score), are you better off with a grade of 81 on this exam or a grade of 68 on a different exam, where the mean is 62 and the standard deviation is 3?  Explain why.